CN1543574A

CN1543574A - Apparatus and method for testing circuit board

Info

Publication number: CN1543574A
Application number: CNA018235336A
Authority: CN
Inventors: ��ķ��; 吉姆·萨贝
Original assignee: MANIA TECH AG
Current assignee: Tec Technologies
Priority date: 2001-08-10
Filing date: 2001-08-10
Publication date: 2004-11-03
Anticipated expiration: 2021-08-10
Also published as: ATE285078T1; EP1415166B1; DE60107881D1; CN100340864C; JP2005517153A; EP1415166A1; WO2003014754A1; DE60107881T2

Abstract

Methods and apparatus are disclosed for detecting manufacturing defects on unpopulated printed circuit boards under test (BUT) utilizing reliable single point current measurement. In a first set of preferred embodiments, an AC signal generator is connected to a signal plate placed under the BUT for applying an electrical field and thereby generating signals in conductors of the BUT. An array of pins mounted on an assembly on top of the BUT at fixed intervals samples currents from the test points on the BUT. In a second set of preferred embodiments, the AC signal generator is connected to the pin array, and the pins apply test signals into the conductive elements of the BUT at fixed intervals. The signal plate detects the electrical field on the BUT. The detected signals are analyzed to discern board faults.

Description

The apparatus and method that are used for testing circuit board

Technical field

The application relates generally to electronic test equipment, more particularly, relates to and utilizes reliable empty (unpopulated) printed circuit board (PCB) of single-point current measurement test so that find the equipment of manufacturing defect.

Background technology

During the manufacturing of printed circuit board (PCB) and processing subsequently, may produce defective, for example open circuit or the short circuit that occur of not wishing in circuit pathways or between the circuit pathways.The fabricator seeking faster always, the method for more accurate and more economical discovery defective.Carry out the automatic detection of empty printed circuit board (PCB) so that realizing workmanship control needs, and have good cost/effectiveness.

Along with integrated circuit and printed circuit board (PCB) become increasingly complex, the test of printed circuit board (PCB) is also more and more difficult.The technology of routine that is used to carry out the printed circuit board test of robotization relates to by one group of testing needle and applies signal and measure output signal on other testing needle.Printed circuit board (PCB) can be tested on " nail bed " tester, this tester comprises the pin that contacts with metallic traces on the tested printed circuit board (PCB), make the input signal that on each node on the printed circuit board (PCB), applies selection, and thereby can on other node on the printed circuit board (PCB), measure corresponding output signal.

Use the highdensity circuit board of traveling probe testing complex.Most of traveling probe testers utilize the probe of limited quantity, mostly are 16 at present most, carry out continuity and short-circuit test.With the same in " nail bed ", traveling probe is some pins, it contacts the metallic traces on the tested printed circuit board (PCB), the input signal of make selecting can be applied on each node on the printed circuit board (PCB), and thereby can measure corresponding output signal on other node on the printed circuit board (PCB).This traveling probe tester provides dirigibility, low cost and does not need stationary installation.The major defect of traveling probe system is the test duration that it is slow.The test of test that this shortcoming makes this tester be restricted to be used for prototype and very little production run.

Also use the high density circuit board of the grid tester testing complex that moves.The grid tester utilization of moving contains several little moving structures of approaching probe.The purpose of this structure is to improve the test speed of this system, makes to be higher than mobile probe system.The major defect of the grid system that moves is that the improvement of its test speed depends on the structure of circuit board, and lacks reliable spot measurement.These shortcomings have negated the improvement than any time of the probe system that moves, and the grid tester that moves is mainly used in prototype and little production run test.

Proposed a kind of selection scheme of a kind of capacitance test method, wherein tested the discharge time or the duration of charging of the part of some charged nets and charged net as traveling probe and grid tester.The shortcoming of this method is that it has finite resolution and relative long Measuring Time.

In the United States Patent (USP) 5218294 of the Soiferman that announces on June 8th, 1993 a kind of printed circuit board test method has been described.Nail bed tester is not used in this technology instruction.This Patent publish utilize AC signal to pass through the power lead of circuit board and ground wire excitation printed circuit board (PCB), near the electromagnetic field of measuring non-contactly near tested circuit board distributes then.The electromagnetic signature of electromagnetism of circuit-under-test plate " feature " and known good circuit board relatively, thereby determine whether the circuit-under-test plate has defective.

Disclosed a kind of other printed circuit board test method in the United States Patent (USP) 4583042 of the Riemer that announces on April 15th, 1986.This Patent publish a kind ofly be used to test the electric continuity of line segment and the circuit board testing system of globality.This system is made of the C meter with a pair of detection terminal, and the elastomeric posterior reference plane of one of them terminal and conduction links to each other, and another calibrating terminal links to each other with test probe.Test probe is an a kind of point probe of single shielding.These detectors measure magnitudes of voltage, and determine line segment electric capacity by the voltage drop between the detecting device.The test probe detecting device moves with respect to test board, so that contact with all test points on the printed circuit board (PCB) in order.

A shortcoming in the system of Riemer is the dependence to circuit-board laying-out, because the position of test point must be determined before surveying.In addition, importantly, in order to measure accurately, the interface between test board and reference planes is no air-gap.

Thereby, need the apparatus and method of the manufacturing defect on a kind of printed circuit board (PCB) of the size detection sky that is independent of circuit board complicacy or network portion in this area.Also require in this area to test any printed circuit board (PCB) in industrial acceptable time.Also need a kind of system of stationary installation of the circuit board that does not need to be exclusively used in test in this area, it is tested that wherein printed circuit board (PCB) is independent of its 26S Proteasome Structure and Function.

Summary of the invention

The some shortcomings that the present invention is directed to prior art provide several solutions.It provides a kind of method of utilizing the manufacturing defect on the printed circuit board (PCB) (BUT hereinafter referred to as) that reliable single-point current measurement detects tested sky flexibly, accurately and fast.It does not need for test b UT fix and move up and down (motion of Z axle).It makes it possible to cancel the position that needed to determine accurate test point before test.

The above-mentioned advantage with other is provided by a kind of tester, and in first group of preferred embodiment, described tester has the AC signal generator that links to each other with the signal plate that is positioned at the BUT below, is used to apply electric field, so as to produce signal in the conductor of BUT.A big array that constitutes by pin, it has the pin more than 128, is installed in fixing interval on the device on the top of BUT, and its sampling is from the electric current of the test point on the BUT.

In second group of preferred embodiment, described AC signal generator links to each other with described pin array, and described pin applies electric current with fixed intervals in the conducting element of BUT.Described signal plate detects the electric field on BUT.

Signal processing apparatus, central computer workstation with and go up the test platform parts in the test macro preferably of placing BUT.Described AC test signals source or link to each other (deciding according to embodiment) with the pin array or with signal plate is so that be provided for faradic signal in BUT.Control module control pin array group component (or " PAA ") is with respect to the motion of BUT.

PAA causes a plurality of test points of sampling with respect to each motion of BUT.By motion control unit and PAA selector unit being sent instruction, receiving measurement result and operation off line fault detection trace routine and BUT position and determine program, the computer control total system.

Each relative motion of PAA all produces the measurement of a plurality of BUT test points.The current measurement that a complete test of these BUT test points produces whole BUT distributes.The size and the geometric configuration of signal that detects and the conductor that is sampled are proportional.Therefore, the measurement on the whole plane of BUT distributes can be processed, thus the test point of perception circuit board.Described signal Processing is extracted correlated characteristic from described distribution, it represents the feature of test point.Fault detection system is the feature of the known or identical non-fault test point on feature and the BUT of the measurement of each test point relatively.The feature of described known test point can obtain from known reference.This measuring of difference that relatively obtains between reference point and BUT test point.Preferably, if difference greater than a predetermined thresholding, then test point is diagnosed as the fault test point.If reference value is less than threshold value, then test point is diagnosed as the non-fault test point.Statistical study can further obtain the more detailed information about the fault of finding, for example position, type etc.

According to one embodiment of the present of invention, pin array group component (PAA) links to each other with AC signal generator, and along with PAA moves with respect to BUT, passes through described pin according to AC signal, preferably once utilize a pin, inject AC signal in the conductor on BUT.Signal plate detects the electromagnetic field by the conductor generation of BUT.

According to an alternative embodiment of the invention, BUT is set on the top of motion conveying belt, and signal plate or be embedded in the conveying belt perhaps is placed in the below of conveying belt.PAA is static.Once more, pin array group component injects signal, and signal plate detects the electromagnetic field of the conductor generation of BUT.

According to an alternative embodiment of the invention, BUT is placed on the top of signal plate, and PAA moves above BUT.Signal plate links to each other with AC signal generator, and signal plate is according to the AC signal radiation field that is applied on the BUT.PAA one next pin is sampled, thereby detects the electric current from the BUT test point.

According to an alternative embodiment of the invention, BUT is placed on the top of motion conveying belt, and signal plate or be embedded in the conveying belt perhaps is placed in the below of conveying belt.PAA is static.Once more, signal plate is according to the AC signal radiation field that is applied on the BUT.PAA one next pin is sampled, so that detect the electric current from the BUT test point.

According to an alternative embodiment of the invention, BUT is placed on the top of signal plate, and PAA moves above BUT.Once more, signal plate is according to the AC signal radiation field on the BUT.A plurality of pins of PAA side by side or are according to priority sampled, so that detect the electric current from the BUT test point.

In first group of embodiment, ac signal which provides signal to the pin of PAA, and described pin contacts with conducting element on the BUT.Described conducting element radiation faradic electromagnetic field on described plate.Represent conducting element to send out size and geometric configuration by the electric current that the electronic circuit of described plate picks up.Described electronic circuit uses the amplifier of high bandwidth, thereby produces Low ESR at described plate, so that high signal to noise ratio (SNR) is provided and is used to detect the ability of the electromagnetic field of the conducting element generation on BUT.In addition, selector switch and high bandwidth amplifier are used in combination, and improve design performance by means of the interference that reduces between the passage.

In other embodiments, ac signal which provides test signal to signal plate, and it is according to the test signal radiation field on the BUT.Electromagnetic field is induction current on the conductive traces of BUT.The pin contact conductive traces of array group component, thus detection is from the electric current of BUT.The electric current that is picked up by pin array electronic circuit is represented the size and the geometric configuration of conductive traces.Described electronic circuit uses high bandwidth amplifier to produce Low ESR on described pin, thus the isolation that between adjacent pin, provides, high SNR and be used to detect ability from the electric current of the track on the BUT.

By means of the whole surface scan that strides across BUT, can obtain the feature of BUT test point.By means of Computer Analysis, can detect manufacturing defect.The current pattern of defect recognition systematic comparison test point and the required pattern of known or identical flawless circuit board.This measuring of difference that relatively obtains between zero defect and defective circuit board.If described difference is greater than predetermined thresholding, then BUT is diagnosed as defective, perhaps unallowable.If reference value is less than threshold value, then BUT is diagnosed as flawless.Statistical study can further obtain the more detailed information about the fault of finding, for example position, type etc.So-called " the known pattern " of flawless circuit board can perhaps obtain by carrying out Theoretical Calculation according to design instruction by testing flawless circuit board with the mode identical with test b UT.Described design instruction is easily from being used to produce the cad tools acquisition of printed circuit board layout.

Description of drawings

Advantage of the present invention and further feature are read following detailed description in conjunction with the drawings and are found out with will be more readily apparent from, wherein:

Fig. 1 is the sectional view according to the simplification of tester of the present invention;

Fig. 2 A be Fig. 1 be used to detect calcspar from the electrical interface of the panel assembly of the electromagnetic field of conductive traces;

Fig. 2 B is the calcspar to pin array group component (PAA) electrical interface of conductive traces injection current of being used for of Fig. 1;

Fig. 2 C be Fig. 1 be used to detect calcspar from the PAA electrical interface of the signal of conductive traces;

Fig. 2 D is the calcspar that is used for applying to track the panel assembly electrical interface of electromagnetic field of Fig. 1;

Fig. 3 is the process flow diagram of expression according to method of testing of the present invention;

Fig. 4 is a side view in the embodiment of the conveyer mechanism that embeds motion or that be set at the signal plate below the travelling belt;

Fig. 5 is the side view of embodiment of the pin array group component of motion; And

Fig. 6 A, 6B are the top views of PAA, and expression is according to the test starting position and the test interval of system of the present invention.

Should be noted that these accompanying drawings are not used in limits the scope of the invention.Here will describe the present invention in detail, should be appreciated that the present invention covers all remodeling, change and the equivalent that drops in the scope that is defined by the claims.

Embodiment

Fig. 1 represents the sectional view of pin array test instrument (PAT) 10.Signal plate 13 is positioned on nonconducting back up pad 12.BUT15 is positioned on the surface 14 of insulation, and the surface of described insulation provides the electrical isolation between signal plate 13 and the BUT15.

Motion 18 links to each other with pin array group component (PAA) 20, and according to the control signal (see figure 2) from computing machine 53 PAA20 is moved with respect to BUT15.Pin 17 links to each other with electrode 19, and contacts by the conducting element 15A of porose back up pad 16 and BUT.

In first embodiment, signal plate 13 is supplied with signal sinusoidal or other waveform by signal generator 11, makes signal plate 13 radiation field in the conducting element 15A of BUT.Described induction current and electric charge on the conducting element 15A of BUT, these electric currents and electric charge detect by utilizing pin 17 samplings.The digital signal processor (see figure 2) is handled the signal of sampling.Then the signal of handling is delivered to computing machine and carry out defect analysis.

In a second embodiment, PAA20 links to each other with signal generator 11, and pin 17 provides electric current according to AC test signals to the test point 15A of the conduction of BUT15.Signal plate 13 detects the electromagnetic field that produces on BUT15.

Fig. 2 A is in second embodiment shown in Figure 1 and the calcspar of electrode 11 that is used to obtain and handle the electromagnetic field that is picked up from the conducting element 15A of BUT15 by signal plate 13 of plate 13 associated.The pin 17 of PAA20 produces electric current at the test point 15A of BUT15.Signal plate 13 detects the electromagnetic field 34 that produces, and produces electric current 30 according to described electromagnetic field 34.Electric current 30 comprises the input signal of electrode 11.

Plate 13 links to each other with the input channel of selector switch 50.Computing machine 53 is by being provided for the select progressively control selector switch 50 of amplifying unit 51 to selector switch.The output channel of selector switch 50 links to each other with amplifying unit 51, and amplifying unit converts the input signal from plate 13 to amplifying signal, and amplifying signal is provided for signal processor (DSP) unit 52 and carries out signal Processing.For example, DSP52 becomes numerical data to the conversion of signals that detects.

Being delivered to computing machine 53 from the signal 32 of the processing of DSP unit 52 stores and analyzes.Selector switch 50 provides the isolation between the amplifying unit 51, and signal becomes bad on big network thereby stop.

Fig. 2 B is the calcspar that is used for applying to the conducting element 15A of BUT15 by pin 17 electrode 19 of test signal in PAA 20 in second embodiment shown in Figure 1.Input channel 36 transmission of selector switch 55 are from the AC test signals of AC signal generator 11.The output channel 38 of pin 17 and selector switch 55 links to each other.Computing machine 53 is by control signal 34 control selector switchs 55.

Fig. 2 C is used for obtaining and handle the calcspar from the electrode 11 of the PAA20 of the signal of the conducting element of BUT15 that is picked up by pin 17 in first embodiment shown in Figure 1.Signal plate 13 produces electric field, and the pin 17 of PAA20 detects electric current on test point 15A.Pin 17 links to each other with the input channel of selector switch 60.Computing machine 53 provides for the select progressively of pin 17 to selector switch 60 by means of control signal 42 and controls selector switch 60.

The output channel 44 of selector switch 60 links to each other with amplifying unit 51, and amplifying unit becomes to offer the signal that signal processor (DSP) unit 62 carries out signal Processing to the current conversion from pin 17 inputs.For example, DSP 62 becomes numerical data to detected conversion of signals.Be transmitted to computing machine 53 for storage with analyze from the signal of the processing of DSP 62.Selector switch 60 provides the isolation between the input pin 17, and signal becomes bad on little network so that avoid.

Fig. 2 D is in first embodiment shown in Figure 1 and calcspar plate 13 associated and that be used for applying to the conducting element 15A of BUT15 the electrode 11 of the electromagnetic field that is produced by signal plate 13.

Fig. 3 is the process flow diagram 300 of expression by the program of the method for testing of computing machine 53 realizations.Process flow diagram 300 expressions are wherein injected test signal by PAA 20 for the analysis of two embodiment shown in Fig. 2 A-C, and detect by signal plate 13, and wherein inject test signal by signal plate 13, and detect by PAA 20.Under each situation, the analysis of being carried out is identical basically.

In the step 330, handle beginning, the parameter of computing machine 53 all PAT of initialization.In the step 331, computing machine 53 order 11 pairs of signal plates 13 of ac generator or PAA20 (according to embodiment) provide test signal 36.In the step 332, computing machine 53 sends movement instruction to motion 18 and 18A, and PAA20 is located with respect to BUT15.

Apply the embodiment of test signal for PAA20 wherein, program continues to be undertaken by following.In the step 333, computing machine 53 sends control signal 32 to selector switch 50, thereby selects to be used to apply the specific pin of test signal.In the step 334, slave plate 13 detected signals are exaggerated unit 51 and amplify, and are handled by DSP52, and are delivered to computing machine 53.

Apply the embodiment of test signal for signal plate 13 wherein, program continues to be undertaken by following.In the step 333, computing machine 53 sends address control signal to selector switch 60, so that the specific pin that selection will be sampled.In the step 334, be exaggerated unit 51 from the electric current of the pin of selecting and amplify, handled by DSP52, and be passed to computing machine 53.

Under each situation, in the step 335, computing machine 53 selections are used to apply signal or are used for the next pin 17 of detection signal.Whether all in the step 336, the pin of selection checked by computing machine 53, for the specific sampling location of BUT15, check all selected mistake of pin.If not, then select next pin.If then pin array group component is moved to next sampling location.In the step 338, computing machine 53 checks whether the test of BUT15 is finished.If do not finish, then for new position repeating step 333-338.In the step 339, computing machine 53 finishes the test of BUT 15.In the step 340, the data that computing machine 53 is analyzed from BUT 15.If the discovery fault, just computing machine 53 is at step 341 indication faults.If the fault of discovery then shows the information of passing through in the step 342.

Fig. 4 is the side view of motion conveying mechanism 60, and BUT 15 is placed on the top of conveying mechanism 60, makes it with respect to PAA 20 motions.The pin 17 of PAA 20 and the conducting element 15A of BUT contact, thereby according to embodiment or induced signal, perhaps measure electric current.

Fig. 5 is the side view of the PAA 20 of motion.Motion 18A moves PAA 20 above BUT15.The pin 17 of PAA 20 and the track 15A of BUT realize contacting, thereby according to embodiment or induced signal, perhaps measure electric current.

Fig. 6 A and Fig. 6 B are illustrated respectively in during the test processes position of PAA 20 before the BUT test.In Fig. 6 A, PAA 20 is positioned at the starting position on the top of the BUT 15 that does not preferably have track 15A.In Fig. 6 B, PAA 20 has been moved and has contacted with the track 15A of selection on the BUT 15.Test point 61 is illustrated in the position of the track 15A of test period pin 17 sampling BUT 15.

The preferred embodiments of the present invention so far have been described, have it will be understood by those of skill in the art that to constitute many different embodiment within the scope of the invention.For example, can make multiple change aspect static at the layout of shape, size, element and the motion of which element, which element.Particularly, " top " and " below " these statements are used by way of example, and do not represent the structure that any reality is required.

Claims

1. method that is used to test and estimate the printed circuit board (PCB) (BUT) of tested sky, described BUT has conductive path and surface, described method is used to test described path and the continuity of the electricity on surface and the continuity of physics, and whether the performance of test b UT meet known standard, said method comprising the steps of:

(a) first side at BUT provides AC test signals, is used for by plate radiated electric field on BUT, and described electric field is induction current and electric charge on the conductive path of BUT and surface;

(b) pass through the electric current of a plurality of pins detections from the conductive surface of BUT on second side of BUT, wherein the relative motion between BUT and described pin produces a plurality of current measurements of described BUT test point;

(c) among mobile described a plurality of pins or the described BUT;

(d) current conversion that detects is become numerical data; And

(e) analyze described numerical data, so that estimate described BUT.

2. the method for claim 1, wherein said plate can move, and described pin is static.

3. the method for claim 1, wherein said pin can move, and described plate is static.

4. method as claimed in claim 3, wherein said pin moves by means of X-Y platform (table).

5. the method for claim 1, wherein said switch process receives the signal from each test point, measure the value of described signal, and change the described analogue value and form numerical data, and wherein analytical procedure according to the defective on the described numerical data diagnosis BUT.

6. method that is used to test and estimate the printed circuit board (PCB) (BUT) of tested sky, described BUT has conductive path and surface, described method is used to test described path and the continuity of the electricity on surface and the continuity of physics, and whether the performance of test b UT meet known standard, said method comprising the steps of:

(a) first side at BUT provides AC test signals by a plurality of pins, so that produce electric current on the conductive path of BUT and surface;

(b) detect electric field by a plate on second side of BUT, wherein the relative motion between BUT and described pin produces a plurality of electric field measurements of described BUT;

(c) among mobile described a plurality of pins or the described BUT;

(d) current conversion that detects is become numerical data; And

(e) analyze described numerical data, so that estimate described BUT.

7. method as claimed in claim 6, wherein said plate can move, and described pin is static.

8. method as claimed in claim 6, wherein said pin can move, and described plate is static.

9. method as claimed in claim 8, wherein said pin moves by means of X-Y platform (table).

10. device that is used to test and estimate the printed circuit board (PCB) (BUT) of tested sky, described BUT has conductive path and surface, and whether its electrical continuity and physics continuity and performance meet known standard will be verified, and described device comprises:

The signal plate adjacent with described BUT;

Be used for providing the signal generator of AC test signals to described signal plate;

Wherein said signal plate is according to described test signal radiated electric field on described BUT, and wherein said electric field induction current and electric charge on the conductive path of described BUT and surface;

The pin array group component (PAA) adjacent with described BUT is used to detect the signal of responding on the conductive path of described BUT and surface, wherein each relative motion between BUT and PAA produces the signal measurement of described BUT test point;

Selector switch is used to be provided at the isolation between the pin of described array group component;

Motion is used to make described PAA to move with respect to described BUT;

Signal processor is used for the conversion of signals that detects is become numerical data;

Computing machine is used to control the motion of relevant pin array group component, and the described selector switch that sorts is stored the numerical data from described digital signal processor, and analyzed described numerical data.

11. device as claimed in claim 10, wherein said AC signal generator are a kind of which amplitude modulation or warbled AC signal generator.

12. device as claimed in claim 10, wherein said PAA comprise the array that the configuration with predetermined of a big one dimension separates.

13. device as claimed in claim 10, wherein said PAA comprise the array that the configuration with predetermined of a big two dimension separates.

14. device as claimed in claim 10, wherein said computing machine comprises the workstation of an operating software, be used to diagnose the defective on the described BUT, and wherein said Computer Analysis receives the signal from each test point, and measure the analogue value of described signal, the described analogue value is converted to digital form, and described digital form is passed to described workstation.

15. device as claimed in claim 10, wherein said PAA pin is made of conductive fiber.

16. device as claimed in claim 10, wherein said PAA and signal plate are set on the opposite side of BUT.

17. a device that is used to test the printed circuit board (PCB) (BUT) of tested sky, described BUT has conductive path and surface, and whether its electrical continuity and physics continuity and performance meet known standard will be verified, and described device comprises:

The pin array group component (PAA) adjacent with described BUT;

Be used for providing the signal generator of AC test signals to described PAA;

Wherein said PAA produces electric current according to described test signal on the conductive path of described BUT and surface;

The signal plate adjacent with described BUT is used to detect the electric field of BUT, and produces output signal according to the electric field that detects, and described signal plate has the insulation course between described signal plate and described BUT;

Wherein each relative motion between described BUT and PAA produces the electric field measurement of described BUT;

Motion is used to make described BUT to move with respect to described PAA;

Signal processor is used for described output signal is converted to numerical data;

Computing machine is used to control the motion of pin array group component, and the described selector switch that sorts is stored the numerical data from described digital signal processor, and analyzed described numerical data.

18. device as claimed in claim 17, wherein said AC signal generator are a kind of which amplitude modulation or warbled AC signal generator.

19. device as claimed in claim 17, wherein said PAA comprise the array that the configuration with predetermined of a big one dimension separates.

20. device as claimed in claim 17, wherein said PAA comprise the array that the configuration with predetermined of a big two dimension separates.

21. device as claimed in claim 17, wherein said computing machine comprises the workstation of an operating software, is used to diagnose the defective on the described BUT.

22. device as claimed in claim 17 wherein uses a broad band amplifier with input selector to produce Low ESR at described pin.

23. device as claimed in claim 17, described PAA pin includes conductive fiber.